Sewing-machine-tension device



(Modeh) J. TRIPP.

SEWING MACHINE TENSION DEVICE.

No. 282,410.- Patented July 31, 1883'.

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A a a .w' 6 1 WITNESSES: lNVENTOR ATTORNEYS.

N, PETERS. Phutu-Lithogmphen Washing. D. c.

p UNITED STATES PATENT OFFICE...

JAMES TRIPP; on NEW YO K, NY, ASSIGNOR T0 CHARLES r. BEOKWITH AND ELLENF. BEOKWITH, BOTH or OBERLIN, OHIO.

SEWING-MACHINE-TENSION DEVICE.

SPECIFICATION formingpart of Letters Patent No. 282,410, dated. July 31,1883. I Application filed Qctobc1' 7 ,1882. (Modem I T0 at whom'it mayconcern Be it known that I, JAMES TRIPP, a citizen of the United States,residing at New York city, in the county and State of New York, haveinvented new and useful Improvements in Sewing-Machines, of which thefollowing is a specification. 1

In a former application I have described a tension device in which thetension may be temporarily removed from the thread by the depression ofa lever. The invention herein set forth is an improvement on thatdevice.-

By this invention the tension on the thread is automatically regulatedby a moving part of the machine, while at the same timethe temporaryremoval of the tension may be easily effected. I

This invention relates to improvements in the tension mechanism ofsewing machines, whereby I i am enabled to clamp the thread tightly inthe tension-disks and hold the same in that position while the needledescends through the goods, the shuttle passes the loop, and the needleagain rises out of the goods and nearly to the point'of its higheststroke. According to my invention, during all the time that the, needleis making its descent, and most of the time (say two-thirds) that it ismaking its upward motion, the thread is held tightly between the disksby means of a revolving cam or surface operating by means of suitableconnecting means-a pivoted lever affixed to or carried by the arm of themachine and supporting the tension disks or plates. When the needle hasascended two thirds (or thereabout) of its upward stroke and has passedout of the goods, a roller orbearingsurface actuating the levercontrolling the lever by which pressure is brought to bear on thefriction-disks'is caused to drop into a recess or lower portion of acam, thereby lowering the pivoted arm and reducing the pressure on thetension-disks and leaving simply a normal tension on the thread, justsufficient to allow of the proper tightening of the thread forming thestitch. I

The object of my invention is to enable the operator to sewoverall-goods, and coarse goods generally, in which-uneven threads areemployed, and also corset and similar thick or starched goods, on thesame machine employed for sewing thin or fancy goods, without thenecessity of the removal or displacement of any of the working parts ofthe machine, by which means, especially when sewing fine or fancy goods,what is commonly known as puckering is avoided by reason of the threadbeing rigidly held during the passage of the shuttle and releasedsubsequently to the proper normal tension for the thinnest goods.

The accompanying drawings represent what I consider the best means ofcarrying out my invention.

Referring to the drawings, Figure 1 is aside View, partlyin section, ofthe head and part of the arm of a sewiug-machine with my improvementsand various other details applied thereto. Fig. 2 is a plan view of thesame. Fig. 3 is an end view of the tension-operating cam and the partsimmediately connected therewith.

In each of the views similar letters of reference are employed toindicate corresponding parts wherever they occur.

A represents the head, and B the arm, of a sewing-machine. Within thehead A, and by preference at the rear of theram or plate 0, operatingthe needle-bar, I form a cam D, the

periphery of which is cylindrical for the greater portion of itscircumference, while between the points 1 1 it is hollowed out for thepurpose of operating a roller or. projection, c,

formed on or affixed to a sliding rod, E. The

cam D. is mounted on the main or driving shaft D.

' In the drawings I have shown the roller 6, pivoted in a bearing-piece,e, which is screwed onto the end of the sliding rod E. The rod E issupported in a groove, f f, formed in a projection, F, by preferencecast with the head A. In the rear of the rod'E is a small stud orprojection, 6 which works in a slot or groove, f, in the front of themain groove f, the object of the projection e and groove f being toprevent the accidental turning of the rod E, and the consequentdisplacement of the roller 6, At its upper end the rod E passes outsideof the head A, and is provided with aspiral or other suitable spring,g,which is adapted to bear against the under side of a a rigid curvedbar, H, which at? is pivoted loosely to a stud or projection, h formedon or affixed to the exterior of the arm B. The curved bar H is formedwith a hole, h, for the passage of the rod E therethrough, as

' shown in Fig. 1.

I is a stud or pin of the ordinary character supported in the upper sideof the arm 13, and which passes up through a hole or aperture, If, inthe bar H.

k k are a pair of tension-disks, the lower one of which rests on theupper surfaceof the curved bar H, which are retained in position on thestud or pin I, in the ordinary manner, by a thumb or binding screw, I.The thread is drawn off from a spool supported in the ordinary or othersuitable manner. It is then conducted around the stud M, carried by thehead A, and thence around and between the tension-disks 7c 70 to a slotor groove, h, formed in the curved bar H. It is then conducted under thebent or hooked bar N to the eye or loop in the upper end of theneedle-bar.

The operation of the device is as follows The shaft D, and consequentlythe cam D, being caused to revolve in the ordinary manner, thecylindrical portion (1 of the cam D bearing against the roller 6 duringall the time the needle-bar and needle are making their descent, andmost of the time (by preference about twotlfirds) that they'are makingtheir upward motion, the curved bar Hwill cause the tensiondisks kk tohold the thread tightlybetween them until the cam D, in itsrevolution,-has brought its cut-away portion (1 under the roller 6, whenthat roller will immediately descend into the cutaway portion d, and bymeans of the rod E draw down the bar H so as to reduce the press-, ureon the tension-disks 7c 70, so as to leave sim-i ply a normal tension onthe thread, just suffi-j cient to allow of the proper tightening of thethread. If at any time the operator wishes to temporarily remove theextraordinary or normal, or both the extraordinary or normal, tension onthe thread, or when he or she wishes to place a new thread between thetensiondisks 7c 7r, it is simplynecessary to press down on thethumbpiece h, when, as will. readily be seen, the curved bar H will bedepressed and the pressure removed from the tension-disks 70 7c.

I It will be evident that the disks k is will be held together withsufficient force or rigidity that no thread can be drawn through themduring a considerable portion of the revolution of the cam D; butimmediately the cut-away portion of the cam D is presented to the rodEthe pressure is lessened and the spring G is allowed to come into play,so as to lessen the pressure on the bar H, and consequently on the disks7c 70.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, 1s

'1. The combination of the tension-disks of a sewing-machine,a slid-ingrod,-a revolving cam operated by the main shaft',-and adapted toperiodically raise and sustain a pivoted bar, by

means of said rod, in position to cause tension on the disks, andaspring interposed between said rod and bar, and adapted to render thepressure upon the disksayielding one, substantiallyas and for thepurpose described.

2. The combination, with the shaft D, cam D,rod E,- and spring g, of theplate-H and tension-disks 70, substantially as and for the purposedescribed.

'3. -In the tension mechanism of a sewingmachine, the combination, withtheplate H, of a bar or rod, E, held in position by means'ofaprojection, e, and a slot or groove, f, substantially as described.

4. The combination, with the plate H, having'agroove or slot, h, for thepassage of the thread, and a thumb-piece, h, of the spring 9 and disks kk, substantially as and for the purpose set forth.

